Planet of the Apes

Anyone doubting our evolutionary tie to other apes should check out that Philadelphia festival of food and fun known as Wing Bowl. The annual event has some striking parallels to behavior outlined in the article “Chimpanzee Hunting Behavior and Human Evolution,” which appeared in the magazine American Scientist.

Chimpanzees sometimes “go on hunting binges, in which they kill a large number of monkeys and other animals over a period of several days or weeks,” the article states. The hunting is done mostly by males, though there are a few female hunters and the party is joined by many other females in estrus (heat), who help turn the event into an orgy of sex and monkey eating.

Wing Bowl, which will take place this Friday, has much in common with this chimpanzee ritual, except the monkeys are replaced by pre-killed chicken wings, and the abundantly fertile females may just be advertising, not delivering.

Beneath the surface, however, there is an essential difference: Top competitors engage in eating feats that push the outer limits of the human body’s capacity, some consuming more than 200 wings within 30 minutes.

From an evolutionary perspective, Wing Bowl, despite its Animal House atmosphere, highlights something uniquely human: The discipline on display here may represent part of what sets our species apart from other animals in our artistic and technological achievements.

The top competitors in Wing Bowl are experienced speed-eating champions, many of them experts at downing hot dogs, hamburgers, eggs, and tacos. Speed eating so fascinated gastroenterologist David Metz that in 2007, he asked one of these champs to perform in his University of Pennsylvania laboratory after swallowing a barium tracer.

Then the speed eater was compared with a “control” — a normal but big guy with a healthy appetite, who ate seven hot dogs and promptly felt sick.

The eating champ, who was 5 feet, 10 inches and then weighed a fit 165 pounds, “consumed two hot dogs at a time to facilitate rapid ingestion,” Metz wrote in a paper published in the American Journal of Roentgenology. “At 10 minutes, the speed eater had eaten a total of 36 hot dogs. His stomach now appeared as a massively distended, food-filled sac occupying most of the upper abdomen.” From the outside, Metz wrote, the man looked pregnant. Over the speed eater’s objections, the gastroenterologist stopped the test, afraid something might burst.

That led Metz of Penn’s Perelman School of Medicine to wonder whether speed eating didn’t reveal a latent form of an ability humans share with predatory animals for whom speed eating is a matter of life or death. While we humans are adapted to eat a so-called omnivorous diet, we share the same basic body plan with other mammals that are natural-born eating champs. The Philadelphia Zoo’s curator of carnivores, Tammy Schmidt, reports lions can eat 50 to 75 pounds of meat at one meal.

Snakes can top this by eating animals that outweigh them, said herpetologist Scott Boback of Dickinson College in Carlisle, Pa. “You’re talking about an animal that can eat 125 percent of its body mass in one sitting,” he said, or more accurately, in one bite. Typical meals for snakes include chipmunks, squirrels, gophers, and rats.

Not all snakes can do this, Boback said, and the first snakes probably didn’t, but around 100 million years ago, mammals started to become more plentiful, offering a food source for any snake that could manage to eat them. Venom is key, since the snake’s dinner selections sometimes have teeth and claws, Boback said.

Rattlesnakes inject their venom and withdraw their heads in time to avoid having them bitten off. The bite not only kills the prey animal, it also acts as a tracer. The victim usually runs some distance away before dying, but the scent of the venom enables the snake to find it.

And then, when it’s time for dinner, the snake’s lower jaw unhinges in the middle, Boback said, enabling the snake to swallow the victim whole and begin digesting it, bones and all.

For the snake, digestion is a race against bacteria, which could cause the victim to rot, he said. To break down the prey, snakes use digestive enzymes similar to ours, but more powerful.

“Snakes do not get reflux,” he said, which is pretty amazing, all things considered.

Still, lions and snakes developed their natural abilities over eons of evolution. For our species, eating 36 hot dogs in 10 minutes or 200 wings in 30 doesn’t come naturally. This is a form not of gluttony, but instead of extreme discipline.

Some of the most formidable eaters are thin, most notably the size-zero Sonya Thomas, also known as the “Black Widow,” who won the Wing Bowl in 2004 with 167 wings. Her resumé includes other victories in which she ate 42 soft tacos in 11 minutes and 65 hard-boiled eggs in 6 minutes, 40 seconds.

The average human body may not seem impressive compared to stronger, faster, more powerful animals, but we humans have discipline, so outliers never fail to amaze, whether they are ultra marathoners, memory champions, or contortionists in Cirque du Soleil. Perhaps lack of discipline could explain why other animals such as elephants and marine mammals show signs of high intelligence but never seem to get anything done — no cathedrals, no cars, no contributions to the Large Hadron Collider, and no space program.

Without discipline, Wing Bowl would really be no different from the chimpanzees’ monkey bowl — just another party.

Contact staff writer Faye Flam at 215-854-4977, fflam@phillynews.com, on her blog at www.philly.com/evolution, or @fayeflam on Twitter.